Removing Schmunk from Banjo Horn

[RickWhite]

Hi all, strange question, but I was wondering if anyone had advice as to one of my winter projects - removing the "schmunk" from my long banjo horn. The schmunk in question is some sort of rust prevention treatment which was prodigiously applied to the entirety of my undercarriage early in the life of the car. On the one hand, I can't complain because it has kept the body extremely rust free and clean, but on the other, it is a thick layer of schmunk.



I was thinking of using a relatively less aggressive paint stripper after I tried to gently peel/chip off the pieces that would cooperate, but I was wondering if anyone had any indication of the stability of the bosch plastic to know if it can withstand some paint stripper (e.g. peelaway or citrus stripper).

Ironically, the horn works well despite all of the crap on it. For whatever reason a previous owner installed true air horns in addition to the banjo horns and I have to admit enjoying scaring the crap out of people blaring all of the horns at once. Since the banjo horns were removed, the air horns are adequate, but not up to the sound level that normally causes people to jump when I hit the horn.

Thanks for your help.

[moito]

Hi all, strange question, but I was wondering if anyone had advice as to one of my winter projects - removing the "schmunk" from my long banjo horn. The schmunk in question is some sort of rust prevention treatment which was prodigiously applied to the entirety of my undercarriage early in the life of the car. On the one hand, I can't complain because it has kept the body extremely rust free and clean, but on the other, it is a thick layer of schmunk.



I was thinking of using a relatively less aggressive paint stripper after I tried to gently peel/chip off the pieces that would cooperate, but I was wondering if anyone had any indication of the stability of the bosch plastic to know if it can withstand some paint stripper (e.g. peelaway or citrus stripper).

Ironically, the horn works well despite all of the crap on it. For whatever reason a previous owner installed true air horns in addition to the banjo horns and I have to admit enjoying scaring the crap out of people blaring all of the horns at once. Since the banjo horns were removed, the air horns are adequate, but not up to the sound level that normally causes people to jump when I hit the horn.

Thanks for your help.

dry ice blasting will do the job...if you have this apparatus handy
a hot air gun probably too...
fuel or nitro-cellulose thinner dip/wipe also
or a combination of those
if you go for dip-make sure not to submerge the painted parts cause this will damage the paint .............and plug the trumpet.

[RickWhite]

Thank you, I will try some combination - anyone know if there is a dry ice blaster that you can send parts to?

I'll update with whatever works. I tried a dremel nylon brush, which worked ok, but looks like it runs the risk of burning through to the plastic.

[LiveFromNY]

We've had very good results with this product:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Soak the plastic horn (only the plastic part) for 24 hours then use a nylon bristle brush to scrape, soak again for a few hours, scrape again. Repeat as necessary. It helps to have some very small brushes to get into the nooks and crannies. We've brought several horns back to a new appearance this way.

[RickWhite]

Thanks, I'll do a little trial with the WD-40 rust remover and some of this stuff:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[BOYER73S]

DRY ICE BLASTING will clean them up a treat and not damage them one bit. Stripper will damage the outer layer of the plastic and you will lose the shine it had from new (ask me how I know)

[LiveFromNY]

DRY ICE BLASTING will clean them up a treat and not damage them one bit. Stripper will damage the outer layer of the plastic and you will lose the shine it had from new (ask me how I know)

I concur. Dry ice blasting would be ideal. But the stripper I recommended is very mild and will not affect the surface of the plastic. Anything harsher and I agree you're risking damaging the part.

[RickWhite]

I had sent a PM to Mr. Boyer in the interest of anti-spam, but given the two votes for dry-ice blasting - anyone have a recommendation for a shop I could send the horn to?

The google maps implies my closest resource is Westchester, more than an hour's drive away. That is fine when there isn't salt on the road, but alas that window has now closed and I'd much prefer driving five minutes to my rural post office than an hour+ (as it inevitably is) to some random vendor.

[doigthom]

Is schmunk a term of art? Does it have anything to do with a frunck?

[Tonger]

I separated the two parts of the horn by removing the screws and submerged the plastic horn part in an ultrasonic cleaner with some cleaning detergent. It worked well and did not damage the plastic. I have a cheap ultrasonic cleaner for small parts - they are easier to find than dry ice cleaners.